linux/net/wireless
Eric W. Biederman 077130c0cf [NET]: Fix race when opening a proc file while a network namespace is exiting.
The problem:  proc_net files remember which network namespace the are
against but do not remember hold a reference count (as that would pin
the network namespace).   So we currently have a small window where
the reference count on a network namespace may be incremented when opening
a /proc file when it has already gone to zero.

To fix this introduce maybe_get_net and get_proc_net.

maybe_get_net increments the network namespace reference count only if it is
greater then zero, ensuring we don't increment a reference count after it
has gone to zero.

get_proc_net handles all of the magic to go from a proc inode to the network
namespace instance and call maybe_get_net on it.

PROC_NET the old accessor is removed so that we don't get confused and use
the wrong helper function.

Then I fix up the callers to use get_proc_net and handle the case case
where get_proc_net returns NULL.  In that case I return -ENXIO because
effectively the network namespace has already gone away so the files
we are trying to access don't exist anymore.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:22 -07:00
..
Kconfig [WIRELESS]: Remove wext over netlink. 2007-04-25 22:29:42 -07:00
Makefile [PATCH] cfg80211: Radiotap parser 2007-07-12 16:07:24 -04:00
core.c [PATCH] cfg80211: fix initialisation if built-in 2007-09-25 22:55:44 -07:00
core.h [WIRELESS] cfg80211: New wireless config infrastructure. 2007-04-25 22:29:41 -07:00
radiotap.c [WIRELESS] radiotap parser: accept all other fields 2007-10-10 16:47:43 -07:00
sysfs.c [PATCH] net/wireless/sysfs.c: Shut up build warning 2007-09-25 22:55:43 -07:00
sysfs.h [WIRELESS] cfg80211: New wireless config infrastructure. 2007-04-25 22:29:41 -07:00
wext.c [NET]: Fix race when opening a proc file while a network namespace is exiting. 2007-10-10 16:49:22 -07:00